Wifi boat data monitor - what's left to measure!

  • Thread starter Thread starter GHA
  • Start date Start date
vas said:
GHA,

sorry to drift the thread a bit, got a fridge related Q for you.

now, since I've got a few in/outs left on my nice JLCPCBs (blue btw looks so much better than green :p ) I was thinking of monitoring my two fridges and sending output to my Garmin 4in displays.
Both fridges use the typical danfoss controller and they both have functional thermostats :rolleyes:
Would the idea be to monitor freezer as well as fridge with normal DS18B20s?
And then turn on and off the right pins on the danfoss controller? (would pull up or down work on teensies, or I need transistors or suchthings though?
Click to expand...
I've 3 ds18b20's on the fridge, cos they're so cheap :) One loose near the bottom which controls the on/off, one on the cold plate and one on the compressor. The thermostat is basically a switch so you need a transistor to turn on/off the compressor. Whach apparently is speed controllable, haven't tried that on my board yet but will be interesting to have a play. The existing arduino displays duty cycle , how much it's been running over the previous 2 hours. With the data getting sent as signalk it will be pretty easy to dig into the data and maybe come up with some programming to get best efficiency.

Your boards look good :cool: - is it all working?
 
GHA said:
I've 3 ds18b20's on the fridge, cos they're so cheap :) One loose near the bottom which controls the on/off, one on the cold plate and one on the compressor. The thermostat is basically a switch so you need a transistor to turn on/off the compressor. Whach apparently is speed controllable, haven't tried that on my board yet but will be interesting to have a play. The existing arduino displays duty cycle , how much it's been running over the previous 2 hours. With the data getting sent as signalk it will be pretty easy to dig into the data and maybe come up with some programming to get best efficiency.

Your boards look good :cool: - is it all working?
Click to expand...
thanks, more Qs then!
3 are fine (got a dozen left I think :D)
do you actually drill the casing or pass them on through the freon pipes to the cold plate and then move them about.
When you say cold plate, somewhere within the theoretical box defined by it, or actually touching the cold plate -not sure tbh on the logic of monitoring temps in there?
compressor you mean compressor housing, or the heat exchanger matrix (on the other side of the 12V fan)?
I do have a L293D for pushpulling the governor via a linear actuator for setting rpm on my yanmar generator, so I can use this chip on the helm box and control the on off of up to 4loads like that, easy :D Even on the generator box, two are doing the linak, one is doing the triggering for the starter and one is triggering the AC out through a massive relay once rpm are at 3K and output is 230V.

Re my boards, got 10boards (100x100mm) one sided (didn't realise that double sided was the same bleeding price and probably spent 3days sorting everything on one side doh!) for 5-6euro iirc as it was my first order and heavily discounted, normal china mail, took 4-5weeks.
Have already built 3, tested them all work fine, really impressed tbh as I'm not a programmer and it was my first ever go at pcb design. OK, I do have 30+ yrs experience in CAD :rolleyes:

when I fit the first 3 (helm one is in operation, main engine and generator are in testing) I'll do a full report either here or in Mobo forum

cheers

V.

edited to say that I've tried the speed control of the danfoss, works, but due to my setup is rather pointless when I use the boat at 30+ ambient...
If I could get a decent and cheap watercooled matrix, that would be another thing, but not 300+ quid for a frigothing
 
Relating to fridge things. I didn't attempt to control the one I installed 3 years ago, but did want to find out how well it was working. I made a data logger with six ds18b20's - I threaded 3 into the fridge, located at top, middle and bottom, and had 3 in the locker with the compressor - one by the bottom air inlet to the locker, one just above the heat exchanger, and one at the top of the locker around the level of the top air outlet from the locker. It helped convince me that it was working ok. As I'm on the UK E Coast, temperatures in the locker are usually not too much of a problem.
 
vas said:
do you actually drill the casing or pass them on through the freon pipes to the cold plate and then move them about.
When you say cold plate, somewhere within the theoretical box defined by it, or actually touching the cold plate -not sure tbh on the logic of monitoring temps in there?
compressor you mean compressor housing, or the heat exchanger matrix (on the other side of the 12V fan)?
Click to expand...
The wires went in the hole where the old thermostat went. Arduino has lasted longer than that did :) One (which does the control) hnaging just off the bottom of the box, another one wedged in behind the cold plate then last one attached to the mesh guard thing round the compressor next to the fan. No rhyme nor reason for placement, just seems vaguely sensible and worked so they've stayed there.


Have already built 3, tested them all work fine, really impressed tbh as I'm not a programmer and it was my first ever go at pcb design. OK, I do have 30+ yrs experience in CAD :rolleyes:
Click to expand...
Same here, electronics & programming knowledge all from google/youtube. And CAD every day back before it was realised that having a job was just silly ;)
Amazing the high degree of resolution and accuracy you can get for so little boat bucks , so much help online and example code to copy. I program in CNP --- cut'n'paste :giggle:. Then fiddle til it sort of works. :cool:

Old plot of the 2 thermometers inside the fridge >
VBS5EhLh.jpg
 
Last edited:
GHA said:
I've 3 ds18b20's on the fridge, cos they're so cheap :) One loose near the bottom which controls the on/off, one on the cold plate and one on the compressor. The thermostat is basically a switch so you need a transistor to turn on/off the compressor. Whach apparently is speed controllable, haven't tried that on my board yet but will be interesting to have a play. The existing arduino displays duty cycle , how much it's been running over the previous 2 hours. With the data getting sent as signalk it will be pretty easy to dig into the data and maybe come up with some programming to get best efficiency.

Your boards look good :cool: - is it all working?
Click to expand...

@GHA Would you be interested in selling one of your fridge boards?
 
You must log in or register to reply here.

Share this page

Top